New organic compounds for use as fuel additives

ABSTRACT

with a linear polyamine of the formula H2N-((CH2)-n - NH)m-R&#39;&#39; in which R1 and R2 are selected from the group consising of a hydrogen atom and a monovalent hydrocarbon radical of 1-30 carbon atoms, R&#39;&#39; is a monovalent aliphatic hydrocarbon radical having 630 carbon atoms, n is an integer from 3 to 10 and m is an integer from 1 to 10.   Useful as gasoline additives are imidic reaction products of a maleic anhydride of the formula

United States Patent [191 Haemmerle et al.

[ Nov. 18, 1975 NEW ORGANIC COMPOUNDS FOR USE AS FUEL ADDITIVES [75] Inventors: Bernard Haemmerle; Bernard Sillion; Gabriel De Gaudemaris, all of Grenoble, France [73] Assignee: lnstitut Francais du Petrole Des Carburants et Lubrifiants, Rueil-Malmaison, France [22] Filed: Apr. 8, 1974 [21] Appl. No.: 459,093

Related US. Application Data [63] Continuation of Ser. No, l27,047, March 22, I971 abandoned.

[52] US. Cl..... 260/3265 FM; 44/63; 260/3265 A;

OTHER PUBLICATIONS Godfrey et al, Chem. Abs. 78, 6339 z (1973). Michael et al. Chem. Abs. 74, 27539 x (1971).

Primary ExaminerDonald G. Daus Assistant Examiner-Mark L. Berch Attorney, Agent, or FirmMillen, Raptes & White ABSTRACT Useful as gasoline additives are imidic reaction products of a maleic anhydride of the formula with a linear polyamine of the formula H,N-l(CH,)-,, NHl -R' in which R, and R are selected from the group consising of a hydrogen atom and a monovalent hydrocarbon radical of l-30 carbon atoms, R is a monovalent aliphatic hydrocarbon radical having 6-30 carbon atoms, n is an integer from 3 to l0 and m is an integer from 1 to l0.

14 Claims, No Drawings NEW ORGANIC COMPOUNDS FOR USE AS FUEL ADDITIVES This is a continuation, of application Ser. No. 127,047. filed Mar. 22, 1971, now abandoned.

This invention is related to fuel compositions containing novel additives.

This invention relates specifically to the use of imidic reaction products of maleic anhydrides and polyamines and alkyl phosphoric acid neutralization products thereof as detergent, antifrost and anti-corrosion additives in fuel compositions. specially those used in sparkignited engines.

Another object of this invention is the use of reaction products of the imidic reaction product type associated with mineral lubricating oils, as additives in fuel compositions. these compounds having cleaning properties in addition to the said detergent, antifrost and anti-corrosion properties.

Many carburation problems are raised by the use of fuels of the gasoline type. particularly in motor-car engines. Thus important deposits are frequently formed on the carburetor elements of motor-car engines. specially in town traffic or at high temperature. These deposits are responsible of misfiring and engine stalling. They are even more troublesome when using devices for the sweeping of crankcase gases knows as Positive Crankcase Ventilation" (PCV), in order to reduce the atmospheric pollution.

When particular hygrometric conditions and air temperatures are met, ice crystals are formed on the walls of the carburetor to which they adhere. They can accumulate in such an amount as to obstruct the passage at the throttle valve level.

Finally, the water dissolved in the gasoline may corrode the metal parts of the engine.

To cope with these difficluties, additives have been added to gasoline in relatively small amounts, for example about 50 parts per million of parts by weight. The main functions of these additives are: to avoid deposits to be formed in the carburetor (detergent effect), to prevent the adherence of ice crystals on the metal walls (antifrost effect) and to form a protective film on the engine parts (anticorrosion effect).

In order to obtain these effects with one molecule only, several additives have been proposed, said additives consisting of organic compounds whose molecule, as a rule, comprises at least one linear portion, soluble in gasoline, and at least one polar portion.

The new organic nitrogen-containing reaction products of this invention, when dissolved in a fuel, form improved detergents, antifrost agents and corrosion inhibitors. and have other advantages which will appear hereinafter.

These compounds are imidic reaction products of a maleic anhydride of the formula with a linear polyamine of the formula m (cm). NH-l-a-R' in which R and R, are selected from the group consisting of the hydrogen atom and the straight or branched mono-valent hydrocarbon radicals, the total number of carbon atoms of R. and R, being from to 30, n is an integer from 3 to 10. m is an integer from i to to and 2 R is a straight or branched, saturated or unsaturated, aliphatic hydrocarbon monovalent radical, the number of carbon atoms being in the range from 6 to 30.

For example maleic anhydride may be reacted with N-oleyl propane diamine or with N-stearyl propane diamine or a mixture of both. Malcic anhydride derivatives, for example dimethyl-, diethylor di-n-butylmaleic anhydride, may be reacted with these diamines or their mixtures.

The reaction may be carried out in an inert solvent, for example an aromatic hydrocarbon or a mixture of aromatic hydrocarbons at a temperature preferably lower than 55C. Benzene, toluene, xylenes and their mixtures may be used.

The water evolving during the reaction may be removed, for example by azeotropic distillation when the selected solvent forms an azeotropic mixture with water.

Furthermore. it has been observed that the reaction products when associated with compounds of alkylphosphoric acid type, increase the number of polar groups and provide for a greater solubility of the additive in the mixtures of aromatic solvents and an improvement of some of the above effects, particularly A the antifrost effect.

The present invention also relates to the compounds resulting from the neutralization of a imidic reaction product with at least one alkylphosphoric acid, as follows:

wherein R" is a straight or branched aliphatic hydrocarbon radical having from 8 to 18 carbon atoms, and p and z are integers such that the total number of the OH groups of the acids is not in excess of the number of amine groups of the imidic amine reaction product.

Among the alkyl phosphoric acids which may be used, the mixtures of monoalkyland dialkyl-phosphoric acids obtained by reacting phosphoric anhydride with an alcohol or a mixture of straight or branched aliphatic alcohols are preferred.

This reaction may be illustrated by the following formulae:

in which R" is a straight or branched alkyl radical having from 8 to 18 carbon atoms. Particular alcohols may be selected so as to obtain a fuel composition which is not liable to extraction with water. Such branched alcohols as. for example, ethylhexyl alcohol may be used in that case.

The neutralization reaction. when applied to a imide reaction product, may be carried out by adding the alkylphosphoric acid to a solution of said imidic reaction product(s) in an aromatic solvent, while maintaining the reaction mixture for several hours at a temperature of about 10 to 65C.

The imidic reaction products, either as such or at least partially neutralized with alkylphosphoric acids, may be added to the fuel compositions at concentrations of IO to 250 and preferably 10 to parts per million of parts by weight, without loss of limpidity.

3 even if added at a low temperature. These compounds may be used in association with usual additives without trouble.

The imidic reaction products of this invention, when used in a fuel composition in association with a small amount of at least one mineral oil, also have cleaning properties. There are used, for example, from 50 to 2000 ppm by weight of a mineral lubricating oil such as, for example. a naphthenic oil and from l to 250 ppm by weight of at least one compound according to this invention.

The following examples are given by way of mere illustration:

EXAMPLE 1 32.4 g of N-oleyl propane diamine (0.1) and 9.8 g of maleic anhydride (0.l mole) are dissolved in 100 ccm of a mixture of toluene and xylene in equal volumes. The solution is heated at reflux until all the reaction water has been carried away by azeotropic distillation. l.8 g of water is recovered and a solution of a reaction product is obtained. The volume of the solution is adjusted to a known volume by means of the above mixture of solvents, so as to obtain a titrated solution.

EXAMPLE 2 17.7 g (about 0.l hydroxy equivalent) of an equimolar mixture of moneand di-octyl phosphoric acids are added to the above solution, the temperature being kept below 65C. The reaction mixture is thereafter maintained at 8085C for l hour under strong stirring. The resulting oily product is diluted to a known volume by means of the 50/50 toluene-xylene mixture, thus resulting in a titrated solution.

EXAMPLE 3 84.6 Kg of xylene, 0.1 Kg of hydroquinone, 83.2 Kg of an equimolar mixture of N-oleyl propane diamine and N-stearyl propane diamine (Trade Mark DINO- RAM S) and 21.5 Kg of maleic anhydride are introduced into a glass reaction vessel of a 200 liters volume. The introduction time is 8 hours at a temperature of 45-50C. The pink reaction mixture is subjected to further heating and, when a temperature of 7Sl 4 80C is attained, the color turns to reddish violet. The temperature is further increased up to the xylene reflux temperature. After 5 hours of azeotropic distillation of water and xylene, 5.2 kg of water are collected.

After cooling, a solution of a mixture of imidic reaction products is obtained. Xylene is added to complete the volume and the resulting solution is divided into two equal fractions.

EXAMPLE 4 One of the fractions of example 3 is admixed with an equimolar mixture of the monoand di-octyl phosphoric acids, in an amount of 19 kg i.e. an amount corresponding substantially to all of the amine groups convertible to salts in said mixture of the imidic reaction products. During this operation, the temperature is maintained below 65C. The stirred reaction mixture is further heated up to 8085C and maintained at this temperature for l hour. The resulting oily mixture is brought to a known volume by addition of xylene.

EXAMPLE 5 Determination of carburetor performance.

4 There is used an engine of the Renault R l6-69 type with a Solex carburetor of the 35 D.I.T.A. 2 type. This engine is lubricated with a conventional 20 W/40 multigrade oil and fed with a premium gasoline whose composition by weight is the following:

- Aromatic hydrocarbons 38 A Olefines I if saturated hydrocarbons 6] 74 This gasoline further contains 0.48 g of lead per liter.

The engine is operated for 48 hours with a l0 to 12% recycling rate of the exhaust gases. About 200 liters of premium gasoline are consumed during each experiment.

In each experiment, there is used a new carburetor (i.e. with a merit of 10). The carburetor is fouled at the end of the experiment and its merit is determined.

The results of the experiments carried out with the use of said premium gasoline are summarized in table I: 1. without detergent 2. with 45 ppm, by weight of the reaction product ofexample 3 3. with 45 ppm by weight of the reaction product ofexample 4 4. with ISO ppm by weight of the reaction product of example 3 5. with ISO ppm by weight of the reaction product of example 3 and 600 ppm by weight of a naphthenic oil having a viscosity of 293.5 cSt at l00F and 16.25 cSt at 2l0F.

The merit increase is the difference between the merits observed respectively with and without additives.

EXAMPLE 6 Carburetor cleaning test The engine and the carburetor type of example I are used again and the carburetor is subjected to fouling by running the engine for 48 hours with the same premium gasoline without additive and by recycling from 15 to 17% of the exhaust gases.

At the end of this fouling period, the merit of the carburetor has decreased from the initial value of 10 to 2.

The engine is operated for 23 more hours under normal running conditions with the use of premium gasoline containing 250 ppm by weight of the compound of example 3 and 600 ppm by weight of the same naphthenic oil as in the above example.

At the end of this operating cycle, the carburetor merit is 6.4, corresponding to a merit increase by 4.4 over the initial merit value of 2 at the beginning of the cycle.

EXAMPLE 7 Carbon Monoxide Content of Off-Gases The carburetor is subjected to fouling, as shown in example 6. Table ll indicates the carbon monoxide content at the beginning of the test and after a 30 hours fouling period.

TABLE II Time Engine speed Ir CO by volume in the off-gases hour 650 rpm, 375 l 300 r.p.m. 3,55

30 hours 650 r.p.m. l 300 r.p.m. 5.3

The engine is then operated at normal running condi tions with the use of premium gasoline containing 250 ppm by weight of the reaction product of example 3 and 650 ppm by weight of the naphthcnic oil of exam- Determination of the anti-frost properties The method was l.F.P.s method as described in Carburants et Combustibles pour moteurs a combus tion interne" by .l. WEISSMAN, Technip editor (1970), the premium gasoline being that of example 5. The additive was as described in example 3 and various concentrations thereof were used. The results are given in table lV.

TABLE IV Fuel icing idling Road Time necessary Time necessary for stalling for stopping (seconds) (minutes) Gasoline alone 40 50 Gasoline 150 ppm of additive 120 60 Gasoline 150 ppm of additive 600 ppm of oil 80 90 60 Gasoline 45 ppm of additive 8O 45 "The ml was the naphthenic ml described in example 5 EXAMPLE 9 Anti-corrosion test (ASTM method D 665 60) EXAMPLES [0 to 20 In these examples, imidic reaction products accord ing to the present invention have been manufactured. These reaction products have been incorporated in gasolines and tested according to the methods ofexamples S to 9.

The reaction products were those obtained by reacting maleic anhydride with a polyaminc of the general formula given hereinbefore, wherein R,, R,, n. m and R are defined as follows:

Example R, R in R [0 CH CH 3 l oleyl l l dodccyl dodecyl 3 t oleyl l 2 H H 5 l stearyl l 3 H H 8 l stearyl 14 H H l0 l oleyl l5 C H (,H, 3 2 oleyl l6 C,H, (.;,H, 3 S oleyl l7 (1H, C H 3 ll) olcyl l 8 H H 3 I hexyl l9 H H 3 I dodecyl 20 H H 3 l eicosyl The results were substantially the same as those of examples 5 to 9 in this specification, stearyl means octadecyl-l (C,,;H31) and oleyl means octadecenyl-l (C,,,H;,

What we claim as this invention:

1. An imidic reaction product of a maleic anhydride of the formula with a linear polyamine of the formula z %l 1)- -lw,

in which R, and R are selected from the group consisting of a hydrogen atom and a alkyl radical of [-30 carbon atoms, the total number of carbon atoms of R, and R being not more than 30, R is 21 alkyl or alkenyl radical having 6-30 carbon atoms, n is an integer from 3 to 10 and m is an integer from t to it), said reaction being conducted in an inert solvent and wherein the water resulting from the reaction is removed therefrom.

2. A reaction product as defined by claim 1, wherein R, and R are CH :1 is 3, m is l, and R is oleyl.

3. A reaction product as defined by claim 1, wherein R, and R are dodecyl, n is 3, m is l, and R is oleyl.

4. A reaction product as defined by claim I, wherein R, and R are H, n is 5, mis l, and R is stearyl.

5. A reaction product as defined by claim 1, wherein R, and R are H, n is 8, m is l, and R is stearyl.

6. A reaction product as defined by claim I, wherein R, and R are H, n is 10, m is l, and R is oleyl.

7. A reaction product as defined by claim 1, wherein O R, and R are C H n is 3, m is 2, and R is oleyl.

8. A reaction product as defined by claim 1, wherein R, and R are C H,, n is 3, m is 5, and R is oleyl.

9. A reaction product as defined by claim 1, wherein R, and R are C H n is 3, m is ID, and R is oleyl.

10. A reaction product as defined by claim 1, wherein R, and R are H, n is 3, m is l, and R is hexyl.

11. A reaction product as defined by claim 1, wherein R, and R are H, n is 3, m is l, and R is dodecyl.

12. A reaction product as defined by claim 1, wherein R, and R are H, n is 3, m is l, and R is eicosyl.

13. A reaction product according to claim l, wherein maleic anhydride is reacted with N-oleyl propane diamine.

14. A reaction product according to claim 1, wherein maleic anhydride is reacted with Nstearyl propane diamine. 

1. AN IMIDIC REACTION PRODUCT OF A MALEIC ANHYDRIDE OF THE FORMULA
 2. A reaction product as defined by claim 1, wherein R1 and R2 are CH3, n is 3, m is 1, and R'' is oleyl.
 3. A reaction product as defined by claim 1, wherein R1 and R2 are dodecyl, n is 3, m is 1, and R'' is oleyl.
 4. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 5, mis 1, and R'' is stearyl.
 5. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 8, m is 1, and R'' is stearyl.
 6. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 10, m is 1, and R'' is oleyl.
 7. A reaction product as defined by claim 1, wherein R1 and R2 are C2H5, n is 3, m is 2, and R'' is oleyl.
 8. A reaction product as defined by claim 1, wherein R1 and R2 are C3H7, n is 3, m is 5, and R'' is oleyl.
 9. A reaction product as defined by claim 1, wherein R1 and R2 are C6H13, n is 3, m is 10, and R'' is oleyl.
 10. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 3, m is 1, and R'' is hexyl.
 11. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 3, m is 1, and R'' is dodecyl.
 12. A reaction product as defined by claim 1, wherein R1 and R2 are H, n is 3, m is 1, and R'' is eicosyl.
 13. A reaction product according to claim 1, wherein maleic anhydride is reacted with N-oleyl propane diamine.
 14. A reaction product according to claim 1, wherein maleic anhydride is reacted with N-stearyl propane diamine. 